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New and Changed Features


This section describes the new features and enhancements to existing features in the Junos OS main release and the maintenance releases for EX Series.


The following EX Series switches are supported in Release 17.1R2: EX4300, EX4600, and EX9200.


In Junos OS Release 17.1R2, J-Web is supported on the EX4300 and EX4600 switches in both standalone and Virtual Chassis setup.

The J-Web distribution model being used provides two packages:

  • Platform package—Installed as part of Junos OS; provides basic functionalities of J-Web.

  • Application package—Optionally installable package; provides complete functionalities of J-Web.

For details about the J-Web distribution model, see Release Notes: J-Web Application Package Release 17.1A1 for EX4300 and EX4600 Switches  .

Release 17.1R2 New and Changed Features

  • There are no new features or enhancements to existing features for EX Series in Junos OS Release 17.1R2.

Release 17.1R1 New and Changed Features


Authentication, Authorization and Accounting (AAA) (RADIUS)

  • Access control and authentication (EX4300-EX4600 mixed VC)—Starting with Junos OS Release 17.1R1, EX4600 switches operating in a mixed Virtual Chassis with EX4300 switches support controlling access to your network using 802.1X authentication and MAC RADIUS authentication.

    802.1X authentication provides port-based network access control (PNAC) as defined in the IEEE 802.1X standard. Supported features include guest VLAN, private VLAN, server fail fallback, dynamic changes to a user session, RADIUS accounting, and configuration of port-filtering attributes on the RADIUS server using VSAs.

    MAC RADIUS authentication is used to authenticate end devices independently of whether they are enabled for 802.1X authentication. You can permit end devices that are not 802.1X-enabled to access the LAN by configuring MAC RADIUS authentication on the switch interfaces to which the end devices are connected.

    Access control features in a mixed EX4300-EX4600 Virtual Chassis are supported only on EX4300 ports.

    This feature was previously supported in an “X” release of Junos OS.

    [See Access Control on a Mixed EX4300-EX4600 Virtual Chassis.]

Class of Service (CoS)

  • Support for classification of multidestination traffic (EX4300)—Multidestination traffic includes BUM (broadcast, unknown unicast, and multicast) traffic and Layer 3 multicast traffic. By default on EX4300 Series switches, all multidestination traffic is classified to the Mcast-BE traffic class mapped to queue 8. Beginning with Junos OS Release 17.1R1, you can classify multidestination traffic to four different queues, queues 8-11, based on either the IEEE 802.1p bits or the DSCP IPv4/v6 bits. You can classify multidestination traffic by including the multi-destination statement at the [edit class-of-service] (to apply globally) or to an individual interface at the [edit class-of-service interfaces interfaces-name] hierarchy. Classification at an individual interface takes precedence over global classification.

    [See Example: Configuring Multidestination (Multicast, Broadcast, DLF) Classifiers.]

  • Firewall filter with policer action as forwarding-class and loss priority (PLP) (EX4300 switches)—Starting with Junos OS Release 14.1X53-D35 and Junos OS Release 17.1R1, on EX4300 switches you can configure the firewall with policer action as forwarding-class and loss priority (PLP). When the traffic hits the policer, PLP changes as per the action rule. The supported PLP designations are low, medium-low, medium-high, and high. You configure policer actions at the [edit firewall] hierarchy level.

    See then (Policer Action)

High Availability (HA) and Resiliency

  • New options for the show vrrp track command (EX Series)—Starting in 17.1R1, the show vrrp track routes command gives you the option to view all tracked routes. Another new option for the show vrrp track command, all, is equivalent to the already existing command show vrrp track.

    [See show vrrp track.]

Interfaces and Chassis

  • LLDP-MED power negotiation (EX4300 Switches) —Starting with Junos OS Release 17.1R1, EX4300 switches support Link Layer Discovery Protocol Media Endpoint Discovery (LLDP-MED) power negotiation with high power (802.3at) devices. LLDP-MED power negotiation enables the PoE controller to dynamically allocate power to an interface based on the power required by the connected powered device.

    [See Power over Ethernet (PoE) Feature Guide for EX4300 Switches.]

  • Half-duplex link support (EX4300 switches)—Starting with Junos OS 17.1R1, half-duplex communication is supported on all built-in network copper ports on EX4300 switches. Half-duplex is bidirectional communication, but signals can flow in only one direction at a time. Full-duplex communication means that both ends of the communication can send and receive signals at the same time. Half-duplex is configured by default on EX4300 switches. This feature was previously supported in an “X” release of Junos OS.

    [See Configuring Gigabit Ethernet Interfaces (CLI Procedure).]

Junos OS XML API and Scripting

  • Support for Python language for commit, event, op, and SNMP scripts (EX Series)—Starting in Junos OS Release 17.1R1, you can author commit, event, op, and SNMP scripts in Python on devices that include the Python extensions package in the software image. Creating automation scripts in Python enables you to take advantage of Python features and libraries as well as leverage Junos PyEZ APIs supported in Junos PyEZ Release 1.3.1 and earlier releases to perform operational and configuration tasks on devices running Junos OS. To enable execution of Python automation scripts, which must be owned by either root or a user in the Junos OS super-user login class, configure the language python statement at the [edit system scripts] hierarchy level, and configure the filename for the Python script under the hierarchy level appropriate to that script type. Supported Python versions include Python 2.7.x.

    [See Understanding Python Automation Scripts for Devices Running Junos OS.]


  • Support for adding non-native YANG modules to the Junos OS schema (EX Series)—Starting in Junos OS Release 17.1R1, you can load custom YANG models on devices running Junos OS to add data models that are not natively supported by Junos OS but can be supported by translation. Doing this enables you to extend the configuration hierarchies and operational commands with data models that are customized for your operations. The ability to add data models to a device is also beneficial when you want to create device-agnostic and vendor-neutral data models that enable the same configuration or RPC to be used on different devices from one or more vendors. You can load custom YANG modules by using the request system yang add operational command.

    [See Understanding the Management of Non-Native YANG Modules on Devices Running Junos OS.]


  • Support for OpenFlow v1.0 and v1.3.1 (EX4600 switches)—Starting with Junos OS Release 17.1R1, EX4600 switches support OpenFlow v1.0 and v1.3.1. OpenFlow v1.0 enables you to control traffic in a network by adding, deleting, and modifying flows in the switch. You can configure one OpenFlow virtual switch and one active OpenFlow controller at the [edit protocols openflow] hierarchy level on each EX4600 switch in the network.

    Also, OpenFlow v1.3.1 allows the action specified in one or more flow entries to direct packets to a base action called a group. The group action further processes these packets and assigns a more specific forwarding action to them. You can view groups that were added, modified, or deleted from the group table by using the show openflow groups command. You can view group statistics by using the show openflow statistics groups command.

    [See Understanding OpenFlow Operation and Forwarding Actions on Devices Running Junos OS.]

Software Installation and Upgrade

  • Support for unified in-service software upgrade (ISSU) (EX9200-6QS)—Starting with Junos OS Release 17.1R1,you can perform a unified ISSU on the EX9200-6QS line card. ISSU enables you to upgrade between two different Junos OS releases with no disruption on the control plane and with minimal disruption of traffic.

    [See Unified ISSU System Requirements.]